FRENCH and Italian researchers have developed a test that may predict altitude sickness - after studying a group of people on the Aiguille du Midi in the Alps.
The findings may could help revolutionise mountain-climbing by predicting who will develop the potentially deadly condition so they can avoid high altitudes, ascend more gradually, or take preventative medication.
Symptoms of mountain sickness include headache, nausea, dizziness, fatigue, loss of appetite, and insomnia. Up to 2% of people develop potentially life-threatening conditions, such as fluid in their lungs or brain.
In their research, the Franco-Italian team studied heart rhythm using in 34 healthy volunteers. Subjects were tested at sea level and again after going by cable car up the Aiguille de Midi to 3,842 meters.
The scientists analysed each subject's oxygen saturation level and heart function, using a portable device, after four hours on the mountain.
After 24 hours at high altitude, 13 out of 34 volunteers developed moderate to severe symptoms. Those same volunteers had lower oxygen saturation levels and their ultrasounds showed poorer heart functioning - and these changes were visible after only four hours at high altitudes. The changes were not seen in people who did not experience mountain sickness symptoms.
One of the study's authors, Dr Rosa Maria Bruno, said: "It is well known that when ascending to high altitude the quantity of oxygen in the air becomes lower and lower
"People going to high altitude, above 2,500m, develop hypoxia, which is a reduced content of oxygen in the blood and tissues.
"Our results suggest that it is possible to identify vulnerable individuals and suggest particular behaviours and drugs only to this subgroup.
"Thus we can limit drug use (and side effects) only to those who will really need them, and give them special advice and recommendations such as avoiding high altitudes or spending more time ascending to allow time for acclimatisation."